The present invention relates to ski binding apparatus with a sole support pivotal about a pivot axis disposed approximately perpendicularly to the ski surface. The present invention is more particularly related to apparatus for securing such sole support against a lifting off from the ski.
Such sole supports mounted on the ski are intended to reduce the friction occurring between the ski boot and the ski during a release operation. The sole supports may have different shapes, however, they are preferably constructed disk-shaped and are rotatably riveted or screwed to a plate for purposes of fastening at the ski. In previously contemplated arrangements, disk-shaped sole supports are rotatably secured to a plate by means of a screw nut accessible when the plate is screwed onto the ski.
In practice, however, it has been found that dirt enters between the sole support and the plate during use, which dirt reduces the easy movability of the sole support and finally blocks the same. The sole support then has to be cleaned again and be provided with lubricant. If the sole support is riveted on, removal for cleaning is not possible. If the sole support is screwed on, then it has to be removed by means of a screw driver. In order to be able to clean the sole support of the type of construction of the above-mentioned previously contemplated arrangements, the plate has to be removed at first from the ski since the head of the screw retaining the sole support is accessible only from the underside of the plate. The excessively frequent required unscrewing of the plate from the ski additionally impairs the durability and life of this threaded connection.
The present invention is therefore concerned with the task to so improve the connecting arrangement sole support described that it can be cleaned in a simple manner.
The present invention contemplates overcoming the above-mentioned problems by providing that the sole support includes axially securing readily detachable securing means so that the sole support can be readily removed from the ski, preferably without the assist of tools.
In preferred embodiments of the present invention, a snap-action or snap-button fastener connection is provided as securing means, which connection also defines the pivot support or pivot axis for the sole support. Such a connection, on the one hand, pivotally secures or fastens the sole support but, on the other hand, can be removed by a simple pulling movement in the direction of the pivot axis. No tool is necessary for the removal since no threaded connection whatsoever has to be disconnected for the removal. A jammed or blocked sole support can thus be rendered operable again in case of emergency also on the ski slopes.
One advantageous embodiment of the present invention provides that a plate is secured on the ski as base support for the sole support which consists at least within the area of the pivot axis of the sole support of a conventional material offering a tenacious elasticity and includes therein an undercut aperture or recess for the accommodation of an enlarged push-button or snap-button portion to be forced into the aperture by a bolt defining the pivot axis of the sole support and fastened to the sole support. This embodiment is characterized by particular simplicity in that no additional clamping springs or the like are required. The bolt can be pressed or riveted into the sole support. The bolt is preferably so constructed that it includes a ring shoulder which abuts the underside of the sole support, and is provided with a head portion whose upper boundary surface is flush with the top side of the sole support or lies below the surface of the sole support. Such a bolt can be permanently connected with the sole support. During the disengagement of the snap-button connection, the head portion absorbs the tensional forces and during closing of the snap-button connection, the forces applied thereby act on the annular shoulder. Since the head portion does not project beyond the top side of the sole support, it does not impair the ski boot during the release operation of the safety binding.
Another advantageous feature of the above-mentioned preferred embodiment provides that the snap-button portion to be forced into the aperture includes two conical sections coaxial to the axis of the bolt and diverging with respect to one another between which is disposed a cylindrical section. Such conical sections can be readily manufactured whereby the angle of inclination thereof predetermines the force necessary for opening and closing the snap-button connection. The cylindrical section disposed between the conical sections prevents the wear of the aperture when the snap-button portion is inserted or pulled out.
Apertures or recesses whose angle of undercut is equal to the cone angle of the conical section to be engaged by the undercut are subjected to lesser wear by reason in particular of the larger contact surfaces.
In another preferred embodiment, an insert element, especially in the shape of a U-shaped spring, is additionally provided as securing means against a lifting off of the sole support. Such an insert element can be pulled out laterally either completely or partially in a simple manner for unlocking purposes or can be inserted for locking purposes.
The use of such a spring has at the same time the advantage that the spring is usable as return spring in order to return the sole support into its center position. This is, in particular, of importance also when a sole plate pivotal on the ski is provided and the sole support is rotatably supported on the sole plate as a rotatable disk. The rotatable disk is thereby able to follow the ski boot as regards its angular position during a lateral deflection of the ski boot by a corresponding pivoting of the sole plate, which is pivotally supported on the ski, for example, in front of the pivot pin of the pivot disk serving for the support of the forward boot portion, whereby the release resistance is reduced and the safety for an orderly release of the binding is increased. With the hitherto customary devices of this type, it was necessary to return the sole plate again into its prescribed center position for the re-engagement of the binding.
In a particularly preferred simple embodiment of the invention, the return spring engages the pivot pin of the pivot disk. Advantageously, the return spring is formed by a U-shaped spring fastened laterally on the ski whose free leg is coupled with the sole plate, especially by means of the pivot pin of the rotatable disk. A particularly simple construction results thereby if the U-spring is supported with prestress on the pivot pin of the sole plate and on a further pin fixed on the ski and arranged preferably between the pivot pin of the sole plate and the pivot pin of the rotatable disk, which spring engages on both sides the two first-mentioned pins as also the further pin.
For the purpose of a further reduction of the friction, the pivotal sole plate is, according to another preferred embodiment of the invention, slidingly supported on a bottom plate fixed on the ski under interposition of a low friction layer, for example, of low friction laminated metal plates having low friction material embedded therein, hereinafter referred to as low friction plates, whereas the return spring is arranged in an aperture or recess of this layer. The plates forming this layer may thereby be inserted, separated into individual disks, loosely into apertures which are formed by the bottom plate or by retaining plates securely connected therewith. A further considerable reduction of the friction results additionally if the rotatable plate is rotatably supported on the pivotal sole plate by interposition of a further low friction layer, especially of "TEFLON" (polytetrafluoroethylene).
These and further objects, features and advantages of the present invention will become more apparent from the following description when taken in connection with the accompanying drawing which shows, for purposes of illustration only, several embodiments in accordance with the present invention.